Controlled morphology barrier elastomers made from blends of syndiotactic 1,2-polybutadiene and ethylene-vinyl acetate-vinyl alcohol terpolymers

ABSTRACT

An elastomer barrier composition comprises a melt blend of syndiotactic 1,2-polybutadiene, a terpolymer of ethylene, vinyl acetate and vinyl alcohol, and a compatibilizing agent. The melt blend is formed under suitable mixing and shear conditions such that the terpolymer exists as a separate domain in generally a flat or plate-like form. The elastomer barrier material can be utilized in rubber compositions such as in the innerliner of the tire.

CROSS-REFERENCE

This is a division of application Ser. No. 07/678,879 filed Mar. 29,1991, of Roger N. Beers, for "Controlled Morphology Barrier ElastomersMade From Blends of Syndiotactic 1,2-Polybutadiene and Ethylene-VinylAcetate-Vinyl Alcohol Terpolymers now U.S. Pat. No. 5,091,467.

FIELD OF THE INVENTION

The present invention relates to a barrier-resistant elastomer havingcontrolled morphology in that a copolymer of ethylene, vinyl acetate,and vinyl alcohol exists as a separate, generally flat or plate-likedomain when blended with syndiotactic 1,2-polybutadiene and acompatibilizing agent.

BACKGROUND

Heretofore, in the field of tires, it is known to use a halobutyl rubberto provide barrier resistance to a gas as in the innerliner portion of atire.

U.S. Pat. No. 4,281,045 discloses multilayered extrusion molding ofexcellent gas barrier property. The layer is formed of saponified EVAand PVA and an adjacent layer of polyolefin.

U.S. Pat. No. 4,362,844, to Lemstra, discloses biaxially stretchedmixtures of crystalline polypropylene and ethylene vinyl alcoholcopolymer having good optical properties and low gas permeability.

U.S. Pat. No. 4,394,473 to Winter, discloses syndiotactic1,2-polybutadiene bags of films for packaging useful for unvulcanizedrubber components having good compatibility and dispersibility in rubbercompounds.

U.S. Pat. No. 4,905,735 assigned to Tokai Rubber, discloses a rubberhose for transportation of cooling medium comprising outer rubber layer,fiber-reinforced middle layer, and inner rubber layer comprising innerand outer rubber layers and an intermediate resin layer.

European Patent 193,823 discloses a co=extruded two-layer bag ofsyndiotactic 1,2-polybutadiene for packaging vulcanized or unvulcanizedrubber or compounding ingredients.

European Patent 337,279 to Ling discloses improved gas barrier structurefor pneumatic articles. The gas barrier structure comprises a gasbarrier film laminated between and bonded to two vulcanizableelastomeric surface layers and is a non-elastomeric polymeric layer.

German Patent 2,341,782 discloses a polyolefin/ethylene vinyl acetatefilm laminate having high resistance to delamination and permeation bygasses.

Japanese Patent 1152061 to Tokai discloses a hose for transportation ofcooling medium comprising inner and outer tube layers, with intermediatefiber-reinforcing layer.

Japanese Patent 1301244 assigned to Tokai Rubber, discloses a hose fortransporting cooling medium comprising an elastic layer of nylon andsaponified EVA copolymer.

Japanese Patent 1308452 discloses a gas-impermeable resin compositioncontaining nylon and saponified product of EVA copolymer. This materialis used as coolant feeding hoses, as packaging and containers for food.

Japanese Patent 1313552 discloses a material comprising 5 to 70 weightpercent of polyolefinic thermoplastic resin, 30 to 90 weight percentolefin/vinyl alcohol resin, 2 to 20 weight percent modified copolymerconsisting of a vinyl aromatic polymer block and conjugated dienepolymer block. This patent discloses the use as a layer of amultilayered food packaging material.

Japanese Patent 5057747 discloses a heat-moldable laminated resin sheetcomprising crystalline polymer sheet, saponified EVA or a polyamidesheet, and non-crystalline polymer sheet laminated with adhesive resin.

Japanese Patent 52141854 discloses a resin molding compositioncomprising solvent-soluble rubbery compound and olefin.

Japanese Patent 53075278 discloses a transparent, heat-shrinkablepolyolefin film produced by a blend of high and low melting resins as atube or sheet, and irradiating the product.

Japanese Patent 54016582 discloses a laminated film comprisingpolyvinylidene chloride saponified polyamide resin or EVA copolymer, andheat-resistant adhesive resin and polyolefin resin.

Japanese Patent 54046281 discloses polymer laminates produced byextruding a blend comprising styrene-based polymer, gas barrier resinand tacky resin.

Japanese Patent 54050084 discloses bonding a laminate of polypropylenelayer and EVA copolymer using methylmethacrylate-butadiene-styreneterpolymer and styrene-butadiene block copolymer adhesive.

Japanese Patent 54057582 discloses a resin laminate with good gasbarrier property comprising EVA copolymer, resin layer containing dieneblock copolymer and olefin copolymer, and a polystyrene layer.

Japanese Patent 54153854 discloses weatherproof polymer compositionshaving good adhesion properties comprising weatherproof polymer andpolymers containing no unsaturation in the main chain, but containingunsaturated side chains and treated with halogen.

Japanese Patent 55149341 discloses a thermoplastic resin compositionused in laminate products prepared from unsaturated carboxylicacid-modified polyolefin, hydroxy group containing polymer and rubber.

Japanese Patent 56123862 discloses a heat adhesive resin film formanufacturing bags by coating aqueous dispersions of ethylene vinylalcohol and PVA on resin film and drying.

Japanese Patent 57028157 discloses a flame-retardant composition basedon non-halogenated polymer containing organopolysiloxane andorgano-metallic compounds.

Japanese Patent 57185341 discloses polybutadiene resin compositionprepared by blending syndiotactic 1,2-polybutadiene resin withdibenzylidene alditols or mono(di)(alkyl) phenyl phosphate.

Japanese Patent 58056822 discloses a primer sheet for liningpolyethylene sheet or steel pipe comprising thermosetting resin andthermoplastic resin with higher melt viscosity.

Japanese Patent 58084836 discloses an agricultural film composition ofhigh fog resistance, transparency, comprising a base polymer of lowdensity polyethylene and EVA, PVA or olefin PVA copolymer.

Japanese Patent 58148761discloses a gas barrier resin laminated with tworesin layers with an adhesive resin layer.

Japanese Patent 59089383 to Motomura discloses a water-swellable packingmaterial comprising rubber, water-soluble polymer, and hydrogel.

Japanese Patent 59157134 discloses a nonflammable composition forcoating electric cables containing EVA or ethylene-ethyl acryliccopolymer, polybutadiene flame retardant, and antimony trioxide, zincoxide and magnesium silicate.

Japanese Patent 59224343 discloses a laminated structure for wrappingfoods comprising saponified EVA copolymer layer and olefin polymer layerin solid rubber.

Japanese Patent 6005237 to Toyobo discloses a laminated polyester filmfor molding containers for food, comprising polyethylene terephthalatefilm, said polymer laminated to surface and sparingly gas permeablematerial.

Japanese Patent 61108653 discloses a polybutadiene composition preparedby mixing crystalline syndiotactic 1,2-polybutadiene with an aqueousdispersion and/or organic solution of elastic polymer.

Japanese Patent 61242841 discloses a laminated oil-resistant vessel forfoods, having saponified EVA layer and thermoplastic resin layer.

Japanese Patent 62158042 discloses a readily heat-sealable plastic filmhaving charge-controlling coating containing carbon black and an acrylicresin layer containing urethane prepolymer.

Japanese Patent 63037132 discloses a flexible film which can be readilyincinerated containing thermoplastic polybutadiene, polyolefin, andinorganic filler, low density linear polyethylene diaper.

SUMMARY OF THE INVENTION

The present invention relates to a blend of syndiotactic1,2-polybutadiene, a copolymer, and a compatibilizing agent, which blendserves as an effective barrier with regard to a gas such as air. Thecopolymer is made from monomers of ethylene, vinyl acetate, and vinylalcohol. The blend is prepared by melt mixing the components withcontrolled morphology wherein adequate shear and/or mixing is utilizedsuch that the copolymer generally exists in a flat, plate-like, orelongated form. Unexpectedly low permeation is obtained due to themorphology configuration of the copolymer within the blend.

DETAILED DESCRIPTION

Syndiotactic 1,2-polybutadiene (i.e., a polybutadiene containing highamounts of syndiotactic 1,2-structure) is commercially available and isalso known to those skilled in the art as well as to the literature.Generally, this compound is formed by solution polymerization utilizingorganic lithium catalyst or coordination catalysts. These catalysts areusually charged under an inert atmosphere of nitrogen or argon beforeuse. Solvents that may be used during the polymerization reactioninclude aromatic, aliphatic, and alicyclic hydrocarbons. Three possiblestructures may be formed in the polymerization of butadiene. Thesestructures include an isotactic configuration in which all the monomerunits add in the same configuration; an atactic configuration in whichthe disposition of the units is random; and a syndiotactic structure inwhich the units are in an alternating configuration. Syndiotactic1,2-polybutadiene (syn 1,2-PBD) is distinguished from otherpolybutadienes in that there is participation of only one double bond inthe polymerization process. The amount of the actual syndiotacticstructure of the so-called syndiotactic 1,2-polybutadiene is generallyat least 80 percent, desirably at least 85 percent, and preferably atleast 90 percent by weight based on the total weight of the threepossible microstructures. The vinyl content of the syndiotacticpolybutadiene can vary from about 82 to 96 percent, desirably from about82 to 92, and preferably from about 82 to 90.

Syndiotactic 1,2-polybutadiene tends to be rigid, crystalline, and haspoor solubility characteristics. The Tg of syn 1,2-PBD will varydepending on the vinyl content and specifically at about 83 percentvinyl content the Tg is about -15° C. The melting point of syn 1,2-PBDvaries with the microstructure and the amount of vinyl groups. Typicalvalues range from approximately 120° C. at about 80 percent vinyl toapproximately 210° C. at about 1000 percent vinyl content.

The amount of the syndiotactic 1,2-microstructure containingpolybutadiene is the weight percent difference of the compatibilizingagent and the copolymer, both of which are discussed herein below.

The barrier copolymer is a thermoplastic resin having very low gaspermeability. The thermoplastic polymer is commercially available and isknown to those skilled in the art as well as to the literature. It ismade from monomers of ethylene and saponified vinyl acetate, wherein theamount of ethylene (that is, repeat units derived therefrom) in thecopolymer is generally less than about 50 weight percent and desirablyfrom about 30 to about 45 weight percent and wherein at least half ofthe vinyl acetate is converted to the alcohol. Such a copolymer iscommercially available under the name of EVAL®, specifically the EPseries, and is manufactured by EVAL Corporation of America. EVAL isgenerally a random copolymer and has the general chemical formula asfollows: ##STR1## wherein the value of x is such that the weight of theethylene repeat groups are, as noted, generally 50 percent by weight orless of the copolymer and the value of y plus z is such that the weightof the vinyl alcohol and the vinyl acetate repeat units is generally atleast 50 percent of the copolymer, and often from about 55 percent toabout 70 percent by weight. The Tg of the ethylene-vinyl acetate-vinylalcohol copolymer is generally below about 65° C., desirably less thanabout 60° C., and preferably less than about 57° C., as from about 50°C. to about 57° C.

The following table portrays various polymer properties for several EVALresins.

                  TABLE 1                                                         ______________________________________                                        POLYMER PROPERTIES                                                                     EP-F101 EP-H101  EP-K102  EP-E105                                    ______________________________________                                        Melt Index,                                                                                 1.3       1.6      2.9    5.5                                   g/10 min.                                                                     Density, g/cc                                                                               1.19      1.17     1.17                                                                                 1.14                                  Melting Point, °C.                                                                181       175      175    164                                      Crystallization                                                                          161       151      151    142                                      Temp., °C.                                                             Glass Transition                                                                          69        62       62     55                                      Point, °C.                                                             Vicat Softening                                                                          173       165      159    155                                      Point, °C.                                                             Heat Distortion                                                                          100        90       90     80                                      Temp., °C.                                                             Ethylene Content,                                                                         32        38       38     44                                      Mol %                                                                         ______________________________________                                    

The preferred EVAL resin is EP-E105. The amount of copolymer isgenerally from about 10 to about 40% weight percent, desirably fromabout 15 to about 30 weight percent, and preferably from about 18 toabout 25 weight percent based upon the total weight of the blend, thatis, the copolymer, the syndiotactic 1,2-polybutadiene, and thecompatibilizing agent. The thermoplastic copolymer generally has ahigher melting point than the elastomer, and a higher viscosity. Themelting point is generally from about 160° C. to about 185° C. Thecopolymer has unique properties not found in copolymers ofethylene-vinyl acetate. Some important physical properties include goodbarrier resistance, and high crystallinity.

In comparison, ethylene vinyl acetate (EVA) polymers are notsatisfactory barriers to air and hence would not provide the necessaryproperties for the present invention. EVA generally melts in the rangeof about 103° C. to about 108° C. and, thus, does not have a highermelting point than the matrix elastomer. As stated above, it isimportant to the present invention that the barrier copolymer have ahigher melting point than the matrix polymer. The formation of a laminarstructure depends on establishing a melted heterogeneous blend ofincompatible polymers so that when the melt is stretched, orientated,one polymer is in the form of a discontinuous phase. To achieve thestructure necessary for forming platelets, it is necessary for thebarrier polymer to be the lesser component and to generally have ahigher melting point and melt viscosity than the matrix polymer.

The blend composition desirably contains an ingredient that functions asa compatibilizing agent in order to achieve improved permeabilityresistance. These compatibilizing agents typically contain from 3 to 12carbon atoms and are usually unsaturated carboxylic acids, anhydrides,or esters thereof; or polymers containing these groups. Specificexamples include maleic acid, methacrylic acid, acrylic acid, ethacrylicacid, fumaric acid, phthalic acid, maleic anhydride, phthalic anhydride,glycidol methacrylate, diethyl maleate, itaconic acid, and the like. Theamount of compatibilizing agent varies, but generally is from about 0.2percent by weight to about 3 percent by weight, and preferably an amountof from about 1 to about 2 percent by weight based upon 100 parts byweight of the elastomer barrier composition blend, that is, thecopolymer, the syndiotactic containing polybutadiene, and thecompatibilizing agent.

A desirable aspect of forming the morphology-controlled barrierelastomer of the present invention involves the mixing of the meltblend. The mixing procedure desirably is such that a laminar morphologyof a thermoplastic component is formed so that even lower permeabilityvalues are obtained. The unexpected low permeability values obtained bythis invention can generally be attributed to these laminarmorphologies. In order to achieve the improved barrier properties, thetwo polymers must be immiscible, i.e., the syndiotactic polybutadieneand the copolymer should have two different Tg's and form a melted,heterogeneous blend. A desired laminar morphology is achieved when thecopolymer exists in an elongated or flat-like configuration as aseparate phase within the melt blend and desirably in substantiallyparallel (i.e., plus or minus 30° or plus or minus 15°) orientations orconfigurations. The length to height ratio of the plate-like copolymerstructures, as an average of the total plate-like structures, isgenerally at least 5, desirably at least 10, more desirably at least 20,and preferably at least 50 with an upper limit being about 200 and evenabout 500. The elongation or stretching can be accomplished by severalmeans such as compression molding, blow molding, extrusion, calendering,or the like. Such elongations have been found to yield the above lengthto height ratio of the plate-like structures.

The mixing device utilized to form the elongated plate-like separatecopolymer phase can be a low shear extruder, a mill, or the like. Thetwo polymers must be mixed together to form a heterogeneous blend of thebarrier material being distributed in the continuous matrix of theelastomer. This is best accomplished by using a low shear process suchas an extruder with a low compression screw generally used for meteringwith low shear rates generally in the range of about 10 to 80 reciprocalseconds, and preferably about 20 to 50 reciprocal seconds. High shearextruders or a Banbury mixer will intensively mix the blend, homogenizethe blend and will not result in platelets or elongated zones of thebarrier polymer and the composition will not have suitable permeabilityfor an effective inner liner. The mixing temperature is generally suchthat the syndiotactic 1,2-polybutadiene melts along with the copolymerto form a heterogenous blend. Such a melting temperature is generallyfrom about 120 to about 210° C. and preferably from about 165 to about1950C During the course of mixing, care must be taken that adequateshear is utilized so as to produce a blend having the above-notedplate-like structures, and overmixing is avoided so that a dispersion orlack of plate-like structures is produced.

The controlled morphology barrier elastomer blends of the presentinvention can be utilized in various elastomers wherein improvedimpermeability to air and other gases is desired, such as in rubbercomponents and goods. A particular end use is within the innerliners oftires, and also in hoses, bladders, containers, and the like. Due to thehigh amounts of syndiotactic polybutadiene utilized, the barriercompositions have good flexibility.

Tire innerliners are generally comprised of any conventional elastomerincluding those known to the art and to the literature, such as forexample butyl rubber which is a copolymer of isoprene and a smallamount, for example less than 10 percent by weight, of isobutylene.Halobutyl rubber made from chlorobutyl or bromobutyl rubbers areparticularly desirable. Moreover, various butyl rubbers can be blendedwith natural rubber to form a suitable tire innerliner material. Thepolyisobutylene portion of the butyl molecular provides a low degree ofpermeability to gases, hence leads to the use of butyl rubber in tireinnerliners.

The invention will be better understood by reference to the followingexamples.

EXAMPLE I (Control)

Syn 1,2-PBD, amount of vinyl approximately 83 percent, was provided as alight yellow powder, and passed through an 80-mesh screen prior to use.Ethylenevinyl alcohol-vinyl acetate copolymer EP E-105 purchased fromEVAL Company of America with a melting point of 164° C. was added. Thepolymers were hand-mixed and vacuum-dried. Melt blending was done usinga Haake Model 40 Banbury mixer at 185° C. with a rotor speed of 50 rpmfor a 5-minute mixing cycle. The shear rate was maintained at about 100sec-1 These blends were intensively mixed. Various compositions wereprepared as summarized in Tables I and II varying in range from 90percent syn 1,2-PBD/EVAL to 10 percent syn 1,2-PBD/EVAL.

The following tables summarize the physical properties.

                  TABLE I                                                         ______________________________________                                        CONTROL BLEND PROPERTIES                                                      NO COMPATIBILIZING AGENT                                                              TENSILE   ELONG.   TEAR  PERMEABILITY                                 SAMPLE  (psi)     (%)      (ppi) (units*)                                     ______________________________________                                        100 SYN 3150      420      714   471                                           90 S/10 E                                                                            3500      391      588   572                                           80 S/20 E                                                                            2776      338      516   662                                           70 S/30 E                                                                            1807      185      404   647                                           50 S/50 E                                                                             395       2       235   402                                           30 S/70 E                                                                             783       2       490    32                                           10 S/90 E                                                                            1095       2       618    1                                           100 EVAL                                                                              8437       5       1814     0.7                                       ______________________________________                                    

                  TABLE II                                                        ______________________________________                                        DSC THERMAL TRANSITIONS                                                       NO COMPATIBILIZING AGENT                                                      SAMPLE          Tm (°C.)                                                                            Tc (°C.)                                  ______________________________________                                        100 SYN         136           98                                               90 SYN/10 EVAL 133, 166     109, 139                                          80 SYN/20 EVAL Broad, 165   109, 140                                          70 SYN/30 EVAL Broad, 166   110, 141                                          50 SYN/50 EVAL None, 168    107, 140                                          30 SYN/70 EVAL None, 166    107, 140                                          10 SYN/90 EVAL None, 166    None, 141                                        100 EVAL        None, 168    None, 141                                        ______________________________________                                    

EXAMPLE 2

Additional blends were prepared by adding 1.5 percent maleic anhydrideto the composition of Example

The maleic anhydride was mixed in situ with the syn 1,2-PBD/EVAL. Aftermixing, the blends were compression molded into 6×6×0.15 inch films.These blends were intensively mixed as in Example 1. The shear rate wasmaintained at about 100 sec-1, using a Banbury mixer.

The following tables summarize the results.

                  TABLE III                                                       ______________________________________                                        BLEND PROPERTIES                                                              1.5% MALEIC ANHYDRIDE                                                                 TENSILE   ELONG.   TEAR  PERMEABILITY                                 SAMPLE  (psi)     (%)      (ppi) (units*)                                     ______________________________________                                        100 Syn 3150      420      714   471                                           80 S/20 E                                                                            3180      216      621   356                                           70 S/30 E                                                                            2814      12       495   280                                           50 S/50 E                                                                            3803      6        626   83                                            30 S/70 E                                                                            5328      4        712   49                                            20 S/80 E                                                                            4930      2        684   33                                            10 S/90 E                                                                            7378      3        1102  20                                           ______________________________________                                         *Permeability units are cc/mil 100 sq. in./24 hrs. at 30° C.           NEED TO DISCUSS THE IMPROVED RESULTS.                                    

                  TABLE IV                                                        ______________________________________                                        DSC THERMAL TRANSITIONS                                                       1.5% MALEIC ANHYDRIDE                                                         SAMPLE           Tm (C.)    Tc (C.)                                           ______________________________________                                        80 SYN/20 EVAL   137        106                                               70 SYN/30 EVAL   152        106                                               50 SYN/50 EVAL   158        106, 122                                          30 SYN/70 EVAL   154        107, 123                                          20 SYN/80 EVAL   163        106, 129                                          10 SYN/90 EVAL   163        None, 131                                         ______________________________________                                    

As apparent from Table III, even though intensively mixed, reductionswith regard to permeability improvement are achieved utilizing smallamounts of a compatibilizing agent in comparison with Table I. Moreover,improved tear strengths and higher tensile strengths were obtainedutilizing the compatibilizing agent.

EXAMPLE 3

An intensively mixed 80/20 EVAL blend was prepared as in Example 2including the compatibilizing agent. The laminar EVAL blends were formedby extruding the mixture at a melt temperature of approximately 185° C.,through a Haake low compression (laminar) screw with L/D of 25:1. Theshear rate was maintained at about 30 reciprocal seconds. The blendswere then extruded through a 4-inch film die producing a film ofapproximately 60 to 80 mils thick and 3 to 3 1/2 inches wide. The filmwas then elongated to double its original size by pressing atapproximately 165° C. between two platelets. The physical properties ofthe comparative blends along with the permeability are shown in Table V.

                  TABLE V                                                         ______________________________________                                        PROPERTIES OF EVAL BLENDS                                                                                50%                                                SAMPLE  TENSILE   ELONG.   MOD    TEAR  PERM                                  RATIO   (psi)     %        (psi)  (ppi) (cc/mil)                              ______________________________________                                        Laminar 3347      271      2271   733   232                                   85/15                                                                         Laminar 2425      151      2101   690    85                                   80/20                                                                         Intensive                                                                             3180      216      2206   621   356                                   80/20                                                                         ______________________________________                                    

As apparent from Table V, a dramatic reduction in the permeability levelwas achieved by obtaining a laminar morphology, that is, a plate-likestructure of the copolymer in accordance with the present invention.

While in accordance with the Patent Statutes, the best mode andpreferred embodiment has been set forth, the scope of the invention isnot limited thereto, but rather by the scope of the attached claims.

What is claimed is:
 1. A barrier composition, comprising:a blend ofsyndiotactic 1,2-structure containing polybutadiene, a saponifiedcopolymer of ethylene, vinyl acetate, and vinyl alcohol, and acompatibilizing agent wherein said compatibilizing agent is on or moreunsaturated acids, esters, anhydrides or derivatives thereof, orpolymers containing unsaturated acids, esters, anhydrides or derivativesthereof.
 2. A composition according to claim 1, wherein the amount ofsaid syndiotactic microstructure in said polybutadiene is at least 80percent by weight based upon the total weight of syndiotactic, atactic,and isotactic structure of said polybutadiene, wherein the amount ofsaid copolymer is form about 10 to about 40 percent by weight, whereinthe amount of said compatibilizing agent is from about 0.2 to about 3percent by weight, and wherein the amount of said polybutadiene is thedifference, all based upon the total weight of said polybutadiene, saidcopolymer, and said compatibilizing agent.
 3. A composition according toclaim 2, wherein the vinyl content of said polybutadiene is from about82 to about 96 percent.
 4. A composition according to claim 3, whereinthe amount of said syndiotactic microstructure is at least 85 percent byweight, wherein said copolymer has a Tg of 65° C. or less, wherein saidcopolymer contains 50 percent by weight or less of ethylene repeatunits, and wherein said compatibilizing agent is an anhydride, or adicarboxylic acid, or an ester thereof, having a total of from 4 to 12carbon atoms, or a polymer thereof.
 5. A composition according to claim4, wherein the vinyl content of said polybutadiene is from about 82 toabout 92 percent by weight, wherein said copolymer has a Tg of 60° C. orless, and wherein the amount of said copolymer is from about 15 to about30 percent by weight.
 6. A composition according to claim 5, whereinsaid copolymer contains from about 30 to about 45 percent by weight ofethylene repeat units, and wherein said compatibilizing agent is maleicanhydride, maleic acid, fumaric acid, methacrylic acid, acrylic acid,itaconic acid, phthalic acid, phthalic anhydride, maleic anhydride,glycidol methacrylate, diethyl maleate, or combinations thereof.
 7. Acomposition according to claim 6, wherein said syndiotactic content ofsaid polybutadiene is at least 90 percent by weight, wherein saidcopolymer has a Tg of from about 50 to about 57° C., wherein the amountof said copolymer is from about 18 to about 25 percent by weight,wherein the amount of said compatibilizing agent is from about 1 toabout 2 percent by weight and wherein the amount of said syndiotacticcontaining polybutadiene is the difference.
 8. A composition accordingto claim 1, wherein said copolymer exists as a separate phase withinsaid blend and has an elongated plate-like structure wherein the lengthto height ratio of said structure is an average of generally at least 5.9. A composition according to claim 3, wherein said copolymer exists asa separate phase within said blend and has an elongated plate-likestructure wherein the length to height ratio of said structure is anaverage of generally at least
 10. 10. A composition according to claim9, wherein said copolymer exists as a separate phase within said blendand has an elongated plate-like structure wherein the length to heightratio of said structure is an average of generally at least
 20. 11. Acomposition according to claim 7, wherein said copolymer exists as aseparate phase within said blend and has an elongated plate-likestructure wherein the length to height ratio of said structure is anaverage of generally at least
 20. 12. A method of producing a barriercomposition, comprising the steps of:a) blending a compositioncomprising syndiotactic 1,2-polybutadiene a saponified copolymer ofethylene, vinyl acetate and vinyl alcohol and a compatibilizing agentwherein said compatibilizing agent is one or more unsaturated acids,estes, anhydrides or derivatives thereof, or polymers containingunsaturated acids, esters, anhydrides or derivatives thereof and b)forming a plate-like morphology with a length to height ratio of atleast 5 to produce the barrier composition.
 13. The method as in claim12, including blending said composition at a low shear rate of fromabout 10 to about 80 sec⁻¹, and wherein the mixing temperature is fromabout 120° C. to 210° C.
 14. The method as in claim 13, wherein theamount of said syndiotactic microstructure in said polybutadiene is atleast 80 percent by weight based upon the total weight of syndiotactic,atactic, and isotactic structure of said polybutadiene, wherein theamount of said copolymer is form about 10 to about 40 percent by weight,wherein the amount of said compatibilizing agent is from about 0.2 toabout 3 percent by weight, wherein the amount of said polybutadiene isthe difference, all based upon the total weight of said polybutadiene,said copolymer, and said compatibilizing agent, and wherein the vinylcontent of said polybutadiene is from about 82 to about 96 percent. 15.The method as in claim 14, wherein the amount of said syndiotacticmicrostructure is at least 85 percent by weight, wherein said copolymerhas a Tg of 65° C. or less, wherein said copolymer contains 50 percentby weight or less of ethylene repeat units, and wherein saidcompatibilizing agent is an anhydride, or a dicarboxylic acid, or anester thereof, having a total of from 4 to 12 carbon atoms, or a polymerthereof.
 16. The method as in claim 12, including blending saidcomposition at a low shear rate of from about 20 to about 50 sec⁻¹, andwherein the mixing temperature is from about 165° C. to about 195° C.